| 1 | Midrib prominent on the upper surface |
| 1' | Midrib impressed in the upper surface. |
| 2 | Twigs hairy. |
| 2' | Twigs glabrous. |
| 3 | Leaves distichous. |
| 3' | Leaves spirally arranged. |
| 4 | Underside of leaves glabrous |
| 4' | Underside of leaves hairy. |
| 5 | Fruits ampulliform. Inflorescence a fascicle. Bracts persistent |
| 5' | Fruits not ampulliform. Inflorescence not a fascicle. Bracts caducous. |
| 6 | Leaves crowded towards the end of the twigs |
| 6' | Leaves evenly distributed. |
| 7 | Underside of leaves glabrous. (If leaf margin and petiole beset with closely spaced vesicular glands: 3. S. adenophylla.) |
| 7' | Underside of leaves hairy. |
| 8 | Seed and embryo twice curved |
| 8' | Seed and embryo uncinately curved towards the base. |
| 9 | Upper side of leaves hairy (pulverulent) |
| 9' | Upper side of leaves glabrous. |
| 10 | Bracts caducous. |
| 10' | Bracts persistent. |
| 11 | Stone smooth. Inflorescence a (basally branched) raceme. |
| 11' | Stone with ridges or grooves. Inflorescence a panicle of 5-30 cm. |
| 12 | Seeds not straight. |
| 12' | Seeds straight. |
| 13 | Leaf index more than 3. Leaf margin (and petiole) beset with closely spaced glands. Stone ellipsoid |
| 13' | Leaf index 2-3. Leaf margin (and petiole) often glandular but glands not closely spaced. Stone ampulliform |
| 14 | Underside of leaves hairy. |
| 14' | Underside of leaves glabrous. |
| 15 | Leaves distichous. Petiole 1-5 mm. Bracts caducous. Seeds straight. |
| 15' | Leaves spirally arranged |
| 16 | Fruits 2-3-celled. |
| 16' | Fruits 1-celled. |
| 17 | Leaves longer than 15 cm. Fruits more than 10 mm long. Leaf margin entire. Nerves 9-14 pairs. Stone with ridges or grooves. Seeds straight |
| 17' | Leaves shorter than c. 15 cm. Fruits to c. 10 mm long. Seed and embryo U-shaped. |
| 18 | Leaves distichous |
| 18' | Leaves spirally arranged. |
| 19 | Inflorescence a panicle of 5-30 cm |
| 19' | Inflorescence not a panicle or shorter than 5 cm. |
| 20 | Fruit stone with high, interrupted ridges which often protrude from the base. |
| 20' | Stone different. |
| 21 | Leaves more than 6 cm long |
| 21' | Leaves shorter than 6 cm |
